A New Method for Measurement of Low-Frequency Noise of MOSFET

In this paper, we present a new method for measuring the low-frequency noise of MOSFET transistors. A closed-loop structure is used in order to bias the MOSFET under test. This method eliminates the need for I-V characteristics of the MOSFET device, transconductance measurement, current source, and current amplifier which are required in a conventional gate-referred low-frequency noise measurement. The proposed method simplifies the low-frequency noise measurement and reduces the cost of the measurement test setup significantly. The proposed method directly measures the gate-referred noise of MOSFET in contrast to the conventional method which measures drain current noise of MOSFET and divides it by MOSFET transconductance. Therefore, the need for accurate measurement of I-V characteristics of the MOSFET is eliminated, leading to the better accuracy of the measured noise. Circuit implementation of the test setup is presented in this paper. Results of this measurement method are compared to those of the conventional measurement method. It has been shown that the results using two methods are comparable.